Speed-changing device for grinding wheels



P. STONER SPEED CHANGING DEVICE FOR GRINDING WHEELS Nom 25, 1924.1,516,895

Nov. 25, 1924 .1,516,895

P. sToNER SPEED CHANGING DEVICE FOR GRINDING WHEELS' Filed Nov. 18, 19203 shuts-sneet 2.

Patented Nov. 25, 1924.

UNITED STATES PATENT OFFICE.

A' PAUL-STONER, 0F WAYNESBORO, PENNSYLTTANIA, ASSIGNOR TO LANDIS TOOLCOM- PANY, OF WAYNEISBORO, PENNSYLVANIA, A CORPORATION F PENNSYLVANIA.

SPEED-CHANGING DEVICE FOR GRINDING WHEELS.

Application led November 1,8, 1920. Serial No. 424,902.

To all whom t may concern:

Be it known that I, PAUL STONER, a citizen of the United States,residing at Waynesboro, in the county' of- Franklin and State ofPennsylvania, have invented certain new and useful Improvements inSpeed- Changing Devices for Grinding Wheels,` of

which the following is a specification. l

My invention relates to a speed changing device for grinding wheels andprovides means whereby the grinding wheel may be driven ata relativelylowy axial speed when first used, and atan increased speed when thewheel has becomev worn down. l

Une object of my invention is to `.provide 4the wheel spindle with atelescoping pulley adapted to run the spindle at different speeds,simple means being provided for changing from low to high speed.

Another object is to provide a safety device whereby the operator isprevented from driving a full sized .wheel at high speed. Referring tothe accompanying drawings which are made a part hereof and on which .3similar reference characters indicate similar parts,

Fi ure 1 is a side elevation of a wheel spin le constructed inaccordance with my invention with the telescoping pulley shown insection;

Iigure 2, a plan view thereof with the casing broken away;

Figure 3, a section on line 3x3 of Figure 2; and 'x Figure 4, a detailsection of the spindle.

In Figure-1, A represents the grinding wheel which is shown as havingbeen worn down far enough to permit it to be operated at high speedwithout danger of breakage due to centrifugal force. A shieldsurrounding the said wheel is indicated at B and is adapted to be movedback as the wheel wears away, being secured in place by a clamp or thelike after such' adjustment. A casing C encloses the telescoping pulley,and its associated parts. K

The spindle has mounted thereon a cylindrical belt receivin member 11which is made secure vthereto y means of a set screw 12 entering anaperture 13` in the spindle. This member 11 4is crowned adjacent to oneend, thus forming a pulley V14 to receive a belt 15 for imparting rotarymotion thereto, while at the opposite end it is adapted toreceive asleeve' 16 splined thereto at 17 and crowned as atl 18 to receive thebelt 15 which climbs the inclined portion 19 when thel sleeve is movedto over- 1e the pulley 14, as shown in Figure 4, andI so imparts aslower speed to the spindle 10 and grinding wheel A. The sleeve 16 isalso provided with an annular flange 20 which is spanned b from a rackbar'` 22 s idably mounted within the casing C. The teeth of the rack barmesh with those ofa segment 24 fastened to a vertical spindle 25 whichis squared at its upper end as at 26 for the reception of a wrench or anoperating handle of any suitable form. The spindle 25 is also providedadjacent the segment with a pinion 27 meshing with'the teeth 28 of asafety locking` bar 29 designed to strike against `a lug 29 on theshield B should the attendant attempt to operate a full sized wheely atthe higher speed. y v

The casing C or a movable portion thereof is provided with two dependinglugs 30 which confine the belt bot-h during the operation ofchanging-the pulleys from the high to the low speed, and vice versa.

s Located within the cylindrical member 1l a yoke 21 depending.

is a yieldable detent 31 designed to enter the `annular groove 32 insleeve 16 when the pul- -leys are set for high speed and to enter thesimilar Groove 33 when in the low speed position. tPins 34 scured to themachine frame or to the floor of the building are shown as passingthrough slots 35 to provide one couventional means for adjustment of thecasing B.

The operation of the device is as follows:

When the wheel A is of full size, it is not desired to have it travel ata very high speed owing to the centrifugal force created therein,therefore when a large size wheelA is in position, the shield B carryingthe lug 29al is in a forward position which places the lug 29 in linewith the safety b-ar 29. This prevents the shifting of the pulley sleeve15 from. the .position shown in higure 4, so that there is little or .nodanger of damage to the wheel A by reason of excessive speed. W'hen thegrinding Wheel has become worn sutliciently the shield B must be movedback to allow the Vwork to contact with wheel A.

rl`he lug 29a is now out of the path of the yond the lug- 29a and at thesame time causes the withdrawal of the sleeve 16 to the position shownin Figures 1 and 2, which permits the belt to run on the smaller pulley14 and impart a high speed to the wheel.

II do not` ropose to limit myself to the specific detalls shown anddescribed, nor to the particular useI have made of my device, as it willbe found useful in other relations and in various modified forms such aswill occur to those skilled in the art. The scope `Of my claims.

Having thus fully described my said invention, what I claim as new anddes-ire to secure by Letters Paent is:

1. In a grinding machine, a spindle, a

` grinding wheel secured thereto, a shield for the wheel, variablespeeddriving means on the Spindle, and means on the shield forcontrolling the operation of the speed varying means.

2. In a grinding machine, a grinding wheel, a speed changing drivingmeans for the wheel, a rod moved by the changespeeddevices, a shield forthe wheel, and

a lug on the shield in position to prevent movement of the rod theshield being adapted to be moved back as the wheel wears Aand thus movethe lug out of the path of the rod.

,3. In combination, an expansible pulley comprisingsa belt receivingmember and 'a belt receiving sleeve adapted to encircle the same or bewithdrawn therefrom, a shaft adjacent the sleeve, connecting meansbetween the shaft and the sleeve, a shield for the grinding wheeladapted to be moved as the wheel wears away, and means connected to theshaft and restrained from movement by the shield in its first position,whereby movement of the sleeve is prevented.

4. In combination, a grinding wheel, driv- ,ing means thereforcomprising a pulley, an

expansion sleeve for the same, and means to move the sleeve to encirclethe pulley com rising a yshaft extending transversel to t e pulley andadapted to be rotate connecting means between the shaft and the sleeve,va slidable rod connectedto the shaft, anda shield for the wheel havinga portion normally in position to prevent movement of the rod, butadapted to be moved out of its path as the wheel diminishes in size.

5. In a grinding machine, la casin a shafttherein, a belt pulley on thesha a sleeve at one end of the pulley adapted to slide underthe belt tochange the speed of invention is shown by the appended'- wheel,change-Spee the shaft, a slidable toothed shifter bar for the belt, asecond toothed slidable bar projecting at one end from the casing, ashaft having a squared head projecting from the casing, rack segments onthe shaft engaging said toothed` bars, and means outside. the casingadapted to en age the second barto` prevent operation of the speedchanging means, substantially as set forth.

6. The combination of an abra-ding device, means for driving the same,speed changing means. including a movable element, and means toprevent'increase of speed of the abrading device until the same has worndown toa predetermined extent said lastnamed means including anobstruction directly in the path of said element of the speed-changingmeans, substantially as set 7 The combination of a. rotary grindingwheel, speed-changing driving means therefor including a reciprocatorypart, and means to prevent change to higher speed including anobstruction maintained directly in the way lofthe-reciprocatory part bysaid wheel so long as the wheel is above a predetermined diameter.

8. In a grindin machine, a grinding wheel, change-Spee driving means forthe, wheel, a rod positioned to be moved by said means in theirspeed-chan ing movement, and a shield for the wheeI adapted to bepositioned to either prevent or permit move- 'ment of said rod,substantially as set forth.

9. In a grindin machine, a `grinding driving means for the wheel, a rodpositioned to be moved by said means in their speed-changing movement,and a stop for the wheel adapted to be posi'- tioned to either preventon permit movement of said rod aecordin to the size of the wheel,substantially as setv orth.

10. In a grindin machine, a grinding wheel, a spindle or driving, it,speedchanging driving means for the spindle, and a shield for thegrinding wheel adjustable to permit or prevent speed-changing movementof said means according to the size of the wheel, substantiallyias setforth.

In witness whereof, I have hereunto set my hand and seal at Washington,District of Columbia, this thirteenth da of November, A. D. nineteenhundred an l twenty.

y fiumiJ s'roNER.

Witnesses: I'

E. W. BRADFORD, F. W. DAnN.

